I've read up on this model from previous threads, and have seen the video, but has anyone on here actually shelled out what it costs to upgrade the E92 to the S3-R? I would be curious to hear what you thought of this mod and whether it was worth it. How much was it and has the price dropped at all? I would consider keeping my E92 for a long time and making it a beastly track car down the road. Is S3-R the way to go?

Thanks.

p.s. for those who didn't know, Dinan is having a sale on software upgrades until the end of this month. 20% off.

There is a jet black E92 S3-R here in Houston that I've seen a couple of times. I didn't know what it was until scott@bmwhn told me. It's surely a sick package if you've got the bankroll for it. I still don't even know what it costs (if it says in that thread, I haven't read through it all) but it has to be a whole lot.

Holy smokes! That's way more than I was thinking. I thought it was in the order of $20,000 some thousand to do the engine, which is the bulk of it? I would not get the wheels or other unnecessary mods.

I'm surprised by the performance results. This was something I was seriously considering.... Already planning on putting all the other Dinan stuff in and thought that adding the bigger engine at the end would be crazy. I mean that M3 with 527 hp / 400+ torque plus Dinan's upgraded LSD (putting torque somewhere in the 450 range) sounds like it would be a helluva quick car. But dropping from 4.6 to 4.2 0-60 and only 3/10ths of a second on the quarter seems far from worth it for that price. I thought an additional 100 hp and almost double the torque would speed that car up to sub 4 seconds and 11s on the quarter. Disappointed... makes it seem like traction is the problem though, so who knows.

I agree. I would not spend that much for minimal gains. If it was half the price, I woudl consider it. Perhaps a s/c is the best way to go.

The appeal to me was a Dinan made NA engine that put that car at over 500hp and 400TQ. I didn't buy the NA M3 so as to turn it into a FI vehicle. That's why I was pleased to see there was an option; but as we've seen it is very overpriced. With labor (and all the other DINAN parts), probably 45k, maybe 50.... that puts my 74k car into the 120s.... I think I'd rather just keep the 45 or 50k and go put a down payment on a 250k car.

The appeal to me was a Dinan made NA engine that put that car at over 500hp and 400TQ. I didn't buy the NA M3 so as to turn it into a FI vehicle. That's why I was pleased to see there was an option; but as we've seen it is very overpriced. With labor (and all the other DINAN parts), probably 45k, maybe 50.... that puts my 74k car into the 120s.... I think I'd rather just keep the 45 or 50k and go put a down payment on a 250k car.

A centrifugal supercharger is very different than turbos or a roots blower. It builds power gradually as the rpm's rise so it retains the NA aspects that we all love so much about these cars.

Any car for $250k is in a completely different league than an M3. They are not mass produced and lose value tremendously with more than a few hundred miles a year. Not to mention the outrageous maintenance an exotic requires.

A centrifugal supercharger is very different than turbos or a roots blower. It builds power gradually as the rpm's rise so it retains the NA aspects that we all love so much about these cars.

Any car for $250k is in a completely different league than an M3. They are not mass produced and lose value tremendously with more than a few hundred miles a year. Not to mention the outrageous maintenance an exotic requires.

They claim an increased 14.9% increase in torque throughout the powerband. I just read over that quickly and didn't stop to think about it.... since its not modifying the actual engine in any way, its just increasing torque it certain parts of the power band where it was previously low? Or is it making more torque available at the wheels? It would be nice if somebody could help clarify that, although I'm sure I'll get a ton of sh** for even asking a question...

And yes, the 250k car comment was a bit out there, but my point being that the cost of this Dinan engine is unjustifiably high in my mind.

The S-3R comes with the stock 3.85 differential. Adding the 4.10 would increase the torque by around 6 or 7%. You can buy the stroker motor for around $20K, but installation will cost you around $10-15K on top of that. Yeah, it's quite expensive...

I have the DCT and the ratio is 3.65, I believe, promising a 14.9% increase in torque throughout the range

They claim an increased 14.9% increase in torque throughout the powerband. I just read over that quickly and didn't stop to think about it.... since its not modifying the actual engine in any way, its just increasing torque it certain parts of the power band where it was previously low? Or is it making more torque available at the wheels? It would be nice if somebody could help clarify that

Adding a shorter rear end gear gets the rpm's higher at a lower speed. It is commonly thought of as a torque multiplier but there is no actual increase in torque. LSD is Limited Slip Differential and has no bearing on final drive ratios.

Nope.. you get a torque increase, with the 4.10 you receive a 6% torque bump. You sacrifice some top speed however. BTW, the M3 GT4 comes with the 4.10 diff....

This is what I thought at first and decided to proceed considering I'm rarely driving 198 through Tampa. GreasyGinzo's post makes sense though.... I must have been wrong in my post somewhere above (about increased overall torque) because the LSD doesn't affect the actual output of the engine in any way; it must affect how that torque is applied to the wheels basically applying more torque at the same speed due to the RPMs being higher for that speed than with the stock LSD (hence the slower top speed).

Yet, the DINAN write-up claims 14.9% (for the DCT 3.65 upgrade) throughout the entire powerband meaning its not just shifting the powerband as I just stated, but actually increasing overall torque output? But my understanding is that that would have something to do with the engine itself, not with the differential.

Obviously I'm not an engineer, but have tried to do some reading about LSDs and Torque. It would be awesome if someone with more mechanical knowledge could explain this better.

Torque is calculated by multiplying flywheel torque by gearing ratio and final drive ratio.

Dinan claims the DCT stock final drive is 3.15:1 and then you can upgrade to 3.62:1. 3.62/3.15=114.9% which is a 14.9% increase.

I took those numbers from the Dinan website and the the torque calculation from a random physics website.

Actual engineers can correct me if necessary.

Well that works out to what they claim.

For you Seattle guys... have you taken your car over for a spirited little cruise on Interlaken close to the Roanoke exit ? Finding myself looking forward to moving back home to Seattle despite the excellent Florida weather.

Torque to the drive wheels is the product of the engine torque, gear ratio and final drive. Actual torque where the wheels meet the road depends on the diameter of the tire but will be limited by the traction of the rubber and road surface -- both of these variable -- not to mention how smoothly power is delivered (driver variable).

I couldn't remember off-hand so I just looked on BMWUSA.COM: final drive ratio with the six speed transmission is 3.85. This means that the transmission output shaft turns 3.85 times for every turn of the wheel axle. If you go to a 4.10 differential then you gain 4.10/3.85, or about 6.5% more torque to the wheels. This is gain from the differential only.

Generally, when giving torque gains for the engine, the manufacturer will pick the RPM that gives the greatest percentage gain. You'll see games played where torque will pick up so many percent at one rpm yet loose some at some other RPM, for a net gain of zero (or thereabouts). The manufacturers won't usually mention any loss unless they display a dyno curve, but even then fudge factors can come into play for a not so completely forthcoming story. Yet even when there is no loss, i.e. gains through the whole rev range, there will still be larger and smaller gains over stock depending on RPM. The manufacturer will pick the RPM that gives the largest gain when reporting it in advertising.

Whether the S3-R gains torque at every RPM I do not know. However, there is no reason to believe it doesn't, since a bigger engine should have more power over the whole rev range, and knowing the good reputation that Dinan has. Also, remember that 0-60 times and such are only one data point and conditions like atmosphere, tires, road surface and driver can affect these times immensely. There are more things to consider when buying a mod than just 0-60 times. Granted, Dinan products are pricey (at least for me), but I wouldn't say they're "overpriced" until I've driven one.